Tips for preparation

Hey everyone, I am fresher(23 batch) currently in a service based company and want to make a switch to PBC once market gets good, so I have chance of upskilling here so what all i wanted to cover are these: 1.Learn Java. 2.Learn LLD. 3.Brush up HLD 4,Brush up DSA.

How much approx time would it take to make them strong if I am strong in DSA and know some of HLD concepts and can design system revolving around that concepts. I have zero idea about Java and LLD and design patterns.

Also if you know any good resources for prep pls put them up here